Pushbutton switch construction with positive plunger safety stop carried by a casing



Aug 4, 1970 R. w. HOLMES 3,523,168

PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, 1968 9 Sheets-Sheet l HIS ATTORNEYS 3,523,168 IVE W. HOLMES S H CONSTRUCTION WITH S TY STOP CARRIED BY A G Aug. 4, 1970 PUSHBUTT PLUN Sheets-Sheet 2 Filed July 26, 1968 FIG-2A INVENTOR. RONALD W. HOLMES HIS ATTORNEYS Aug. 4, 1970 R. w. HOLMES 3,523,168

PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, 1968 9 Sheets-Sheet 5 FIG-4 58 x 5 so INVENTOR.

I00 74 RONALD w. HOLMES H as ATTORNEYS R. w. HOLMES Aug. 4, 1970 3,523,168 PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, 1968 9 Sheets-Sheet 4 FIG-4A 72 n u wl) 9 .1 n l I 1.]! 4 A U m L l L/h w Q 2mm I: 11H... 8 2 z 9 l 0 V HFOJ 2 I72 1, WM

6 l A 2 AL I n 2 FIG 6A INVENTOR. RONALD} w. HOLMES I MW) {I26 I02 H0 H2 IIOA H IS ATTORNEYS Aug. 4, 1970 R. w. HOLMES 3,523,163

PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, 1968 4 9 Sheets-Sheet 5 FIG-5 INVENTOR. RONALD W. HOLMES HIS ATTORNEYS R. w. HOLMES 3,523,168 IUSHBUTTON SWITCH CONSTRUCTION WITH POSJT'IVI'J Aug. 4, 1970 PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, L968 5) Sheets-Sheet 7 FIG-7 HIS ATTORNEYS Aug. 4, 1970 R. w. HOLMES 3,523,168

PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26. 1968 9 Sheets-Sheet 8 FIG-8 INVENTOR. RONALD W. HOLMES HIS ATTORNEYS Aug. 4, 1970 R. w. HOLMES 3,523,168

PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Filed July 26, 1968 9 Sheets-Sheet 9 3 FIG-9 INVENTOR. RONALD W. HOLMES HIS ATTORNEYS United States Patent 3,523,168 PUSHBUTTON SWITCH CONSTRUCTION WITH POSITIVE PLUNGER SAFETY STOP CARRIED BY A CASING Ronald W. Holmes, Freeport, Ill., assignor to Robertshaw Controls Company, Richmond, Va., a corporation of Delaware Filed July 26, 1968, Ser. No. 748,017 Int. Cl. H01h 3/12, 3/20, 9/18 US. Cl. 200--159 21 Claims ABSTRACT OF THE DISCLOSURE This application discloses an illuminated pushbutton switch construction having a tubular casing that receives a pushbutton construction means at the upper casing end and has a lower switch means at the lower casing end. The pushbutton construction means is movable inward into the upper casing end by an initial pushing in action and thereafter movable upwardly by a release counterspring action. This places the pushbutton construction means in operable locked condition to operate the switch means as often as desired. The pushbutton means may be removed from the casing by an upward or outward movement, followed by an inward, downward pushing action of the pushbutton construction means. Thereafter, the pushbutton means may be removed from the casing by an upward and outward removing action completely to remove the pushbutton from the casing. The pushbutton construction means is prevented from actuating the switch means during the initial introduction of the pushbutton means into the casing by a positive stopping action of the switch operating plunger and its supporting structure and the push button can only operate the switch means after the plunger has been released from the first pushing in action.

This application relates to a pushbutton switch construction with a positive plunger safety stop.

One of the features of this invention includes a construction in which a pushbutton construction means is introduced into the upper end of a casing and is then released to place the pushbutton construction means in operable locked condition to operate a switch means at the lower end of the casing. The pushbutton means cannot operate the switch means during the first or initial introduction of the pushbutton means into the casing because the pushbutton is stopped by a positive plunger stop but can operate the switch means as often as desired after the pushbutton construction means has been released from the first or initial pushed in position, because the positive plunger stop has been rendered inoperative by said release of said pushbutton construction means.

Another feature includes a construction whereby the pushbutton construction means may be removed from the casing by a pulling out action followed by a pushing in action.

Another feature of this invention includes a construction in which a plunger is provided at the lower end of the casing to actuate the switch means, with said plunger having positive stop means to stop said plunger during the initial pushing in action of said push button construction means.

Other features of this invention are apparent from this description, the appended claimed subject matter, and/or from the accompanying drawings in which:

FIG. 1 is an exploded diagrammatic perspective view of an illuminated switch construction according to this invention.

FIG. 2 is a cross section taken along the line 2-2 of FIG. 4.

'ice

FIG. 2A is a diagrammatic perspective cross section taken along the line 2A2A of FIG. 4.

FIG. 3 is an exploded perspective view of certain parts shown in FIGS. 2 and 4.

FIG. 4 is a diagrammatic vertical cross section of the casing, pushbutton construction means, and plunger controlling construction at an early stage of the initial pushing in action of the pushbutton construction.

FIG. 4A is a fiat development view of certain parts of FIGS. 2, 2A and 3 in the condition which they have in FIG. 4.

FIG. 5 is a view similar to FIG. 4 and showing the parts at a later stage of the initial pushing in action.

FIG. 5A is a view similar to FIG. 4A but showing the parts in the stage of FIG. 5.

FIG. 6 is a view similar to FIG. 5 but showing a stage of operation later than that of FIG. 5, with the pushbutton construction locked and ready for switch means actuation and switch means unactuation.

FIG. 6A is a view similar to FIGS. 4A and 5A but showing said parts of FIGS. 2, 2A and 3 immediately after a slight release of the pushbutton construction means from the position of FIG. 5A.

FIG. 6B is a view similar to FIG. 6A but showing the parts when the plunger is pushed down to switch means actuating position shown in dotted lines in FIG. 6.

FIG. 7 is a cross section transverse to FIG. 6 and taken along line 7-7 of FIG. 6.

FIG. 8 is a view similar to FIG. 6, but showing the push button pulled out to the dotted line position shown in FIG. 7.

FIG. 9 is a view similar to FIG. 8 but showing the pushbutton slightly pushed into cause the releasing action for the pushbutton, which pushbutton may then be completely pulled out with the lamp holder to the position of FIG. 1.

FIG. 9A is a view similar to FIGS. 4A-6B but showing the parts in full lines in the condition of FIG. 9, and in dotted lines in the condition after the pushbutton construction means has been removed from the casing.

FIG. 10 is an upward plan view of certain parts taken along the line 10-10 of FIG. 6 and with one of the lamps omitted.

Certain words, which indicate direction, relative position, and the like, are sometimes used in this application for the sake of brevity and clearness. However, it is to be understood that these words are used only in connection with the views in the drawings, and that in actual use the parts so described may have entirely different direction, relative position, and the like. Examples of such words are vertical, horizontal, upper, lower, etc.

An embodiment of this invention may include a casing 20 which may be a tubular casing. The casing 20 may have an upper pushbutton construction means receiving upper end or aperture means 22 and a lower switch means receiving second casing end 24. A pushbutton construction means 26 is movable inward relatively to said upper casing end 22 by an initial pushing in action, such as shown sequentially in FIGS. 4 and 5.

The pushbutton construction means 26 is positively stopped at the position of FIG. 5. This positive stopping action includes a positive stopping action of the lamp holder 28 or lamp holder section or means 28 of the pushbutton construction means 26, and also by a positive stopping action of the pushbutton or pushbutton section or means 30 of the pushbutton construction means 26.

The lamp holder section or means 28 is positively stopped during the initial pushing in action by the casing positive stop means or corner stops 32, which are engaged by the corners of the lamp holder 28, as in FIG. 5.

The pushbutton or pushbutton section or means 30 is positively stopped during the initial pushing in action by positive stop means, to be more fully described, and which includes a switch actuating plunger 34, and a switch plunger support means 36 carried by the casing 20 independently of said pushbutton construction means 26, to stop said switch actuating plunger 34 and a pushbutton plunger construction 38, 40 in the switch means unactuating position shown in FIG. 5. This positively stops the pushbutton section 30 in said switch means unactuating position of FIG. 5.

After the initial pushing in action of FIGS. 4 and 5, the pushbutton 30 may be released by the operator so that the pushbutton 30 is movable upwardly slightly from the position of FIG. 5 to the position of FIG. 6. This renders said stop means inoperative to stop the plunger 34 in the switch unactuating position of FIG. 5 and full line position of FIG. 6 and releases the plunger 34 to be movable to the switch actuating position 34A, which is shown in dotted lines in FIG. 6 so that the pushbutton 30 is pushed down by the operator after such release. Thereafter the operator may push the pushbutton 30 down and release the same as often as desired to actuate and unactuate the switch means 44 by the actuator 42 of the switch means 44 as often as desired, as indicated by the full line and dotted line showing of switch actuating plunger 34, 34A.

The locking of the pushbutton construction means 26 in the casing is also shown in FIG. 6 with the preliminary steps leading thereto being shown in FIGS. 4 and 5.

The initial pushing in step is shown in FIG. 4 where the pushbutton and the lamp holder 28 are pushed downwardly by the operator. The pushbutton legs 46, FIGS. 1 and 7, have their lower hooks 48 in the upper groove 50 of the lamp holder 28 so that the narrow neck 52, FIG. 4, between the plungers 38 and 40 allows the inwardly spring pressed latching arms 54 to be pressed inwardly by the compression springs 56 so that the outer locking hooks 58 of the arms 54 pass inside the locking brackets 60 which are carried by casing 20. The plungers 38, 40 and neck 52 are fixed and secured to the lower part of the pushbutton 30 by any suitable construction, such as shown, including a cross bar 62, FIGS. 1 and 4, which may be welded to the ring 64 which is fastened to the upper end of the plunger 38.

The locking operation of the lamp holder 28 is continued as shown in FIG. 5. The frusto cone 66 of plunger 38 has pushed the arms 54 outwardly from their inward position of FIG. 4 to the position of FIG. 5. The hooks 58 have been moved under the locking brackets 60. This has been accomplished by the continued downward push by the operator on the pushbutton 30. The lamp holder 28 has been positively stopped by the corner stops 32 of casing 20. The pushbutton 30 has been positively stopped by the action of the pushbutton plungers 38 and 40, neck 52 and the positive stop action on the switch actuating plunger 34 by the plunger support means 36 to be described.

The lamp holder locking operation is completed, as shown in FIG. 6. The pushbutton 30 has been released upward by the operator, and this has allowed the compression springs 67 of the lamp contactors 69 to push the lamp holder 28 upward slightly, so that the locking hooks 58 have locked under the locking brackets 60 and have firmly locked the lamp holder in the position of FIG. 6 against upward and outward movement.

In the full line position of FIG. 6, the pushbutton 30 may be pushed inwardly and downwardly to cause a downward pushing action on the pushbutton plungers 38 and 40 to push downwardly the switch actuating plunger 34 through the medium of a cam or cam means 68 and its fingers or finger means 70 in a manner to be more fully described. The plunger 34 may be pushed down to the dotted switch actuating position 34A, so that the 4 switch actuator 42 may be pushed down to the dotted switch actuated position 42A to actuate the switch means 44.

Thereafter the operator may alternately push in and release the pushbutton 30 from the position of FIG. 6 to actuate and unactuate the switch means 44 as often as desired.

The switch means 44 is supported from the casing 20 by any suitable means, such as bracket means 72 which may be inverted U-shaped, if desired, and be detachably secured to the casing 20 by a resilient hook construction 74 which also may be inverted U-shaped. The switch means 44 is supported from the downward arms of the bracket 72 by suitable fasteners 76, FIG. 7, which may be screws, rivets, or the like.

The switch means 44 may have electrical connectors 78 which may be connected to any circuit to be controlled by the pushing in and releasing actions of the pushbutton 30. A plurality of illuminating lamps may be part of such circuit and may be controlled by the switch means 44 and pushbutton 30 in any well known manner. Some type of circuit may connect the connectors 78 to one or more of the connectors 79 which are bent horizontally at 79A, FIGS. 6 and 7, and which are electrically con nected to the lamp contacts 69 and lamp contact buttons 81.

A neutral plate 83, FIGS. 6 and 10 may be provided under the lamp holder 28 which may be contacted by one or more neutral contactors, not shown, which may be similar to contactors 69. This plate may have neutral tongues which engage the neutral sleeves 85A of the lamps 80.

Whenever it is desired to change or replace any one or more lamps 80, the pushbutton construction means 26 may be removed from the casing 20 to the position of FIG. 1, so that such lamp or lamps 80A may be removed and/ or replaced.

The pushbutton construction means 26 may be re moved from the casing 20 by the steps shown in FIGS. 7-9 and 1.

The pushbutton construction means 26 may be released and removed from the locked condition shown in full lines in FIGS. 6 and 7, by an initial pulling out action on the finger notch, FIG. 6, of the pushbutton 30, to the position shown in dotted lines at 48A in FIG. 7 and in full lines in FIG. 8. This brings the neck 52, FIG. 8, in alignment with the locking arms 54 and places the hooks 48 in the dotted line position 48A of FIG. 7. Then a slight pushing in action on the pushbutton 30* and on the lamp holder 28 is produced by the operator to the position of FIG. 9. This pushes the locking arms 54 and their hooks 58 below the locking brackets 60, so that such arms 54 and hooks 58 are pushed inwardly by the compression springs 56 acting on the shoulders 82 of lamp holder 28 and on the discs 84 which are secured to the arms 54.

The slight pushing in action of the pushbutton 30 and lamp holder 28 in FIG. 9 releases button 30 and holder 28 so that they can be pulled out as a unitary pushbutton construction means 26 completely out of casing 20 to the position of FIG. 1. Any one or more lamps 80 may then be replaced or adjusted, as indicated in FIG. 1.

Thereafter the unitary pushbutton construction means 26 may be reinserted into the casing 20 at the upper casing end 22. Then the operations of FIGS. 4-6, which have been previously described, can be repeated. This includes the reactivation of the positive stop means to stop the plunger 34 in unactuating position during this repeated or subsequent initial pushing in action.

THE POSITIVE STOP BY CAM MEANS 68 Positive stop means in the plunger support means 36 is produced by the cam means 68 to stop said plunger 34 in switch means unactuating position during the initial locking pushing in action, as shown in FIGS. 4, 4A, 5, and 5A. The stop inoperative rendering means responsive to the initial release of the pushbutton 30 to render said positive stop means inoperative to stop said plunger 34 in unactuating position is shown in FIGS. 6, 6A and 6B. The details will now be further described.

Said positive stop means and stop inoperative rendering means may include a serrated member 86, with downward serrations 87 which may be the central part of the lamp contact block 88 which holds the lamp contacts 69. See FIGS. 2, 2A, 3 and 4. Such means may also include the rotatable cam or cam means 68 with its fingers or finger means 70. Such positive stop means and stop inoperative rendering means may also include the plunger 34 with certain parts including an upper plunger disc 90, which has an upper flat surface 92 with a plurality of ridges 94. Such disc may also have a plurality of teeth 96. The plunger 34 and its said parts 90, 92, 94 and 96 reciprocate together vertically but are locked against substantial relative rotation with respect the serrated member 86, and a cylindrical case or plunger guide means 98 that is secured to the bottom floor 100 of the casing 20.

Such plunger guide means 98 may have a plurality of grooves 102 and 119 in which the teeth 96 of plunger disc 90 reciprocate vertically so that the plunger 34 can not substantially rotate relatively to the plunger guide means 98. The guide means 98 also has an upper circular edge or end 104 above the grooves 102. The guide means 98 is enlarged radially outwardly at 106 to provide shoulders 108 to hold the upper end 104 and lower bottom 109 of plunger guide means 98 between the lamp contact block 88 and the bottom floor 100 of the casing 20.

The plunger guide means 98 has a plurality of slanting upper surfaces 110 which extend from slightly below and inward of the end 104 of guide means 98 to a plurality of stop notches or offsets 112. Then a plurality of continuing lower slanting surfaces 114 extend into the grooves 102. A plurality of inward columns 116 and 118 are provided below the slanting surfaces 110 and 114 to provide inwardly extending side walls to produce the grooves 102 and 119 between the columns 116 and 118. The teeth 96 of the plunger disc 90 can reciprocate in the grooves 102 and 119, and the fingers 70 can reciprocate in grooves 102.

The fingers 70 of the cam 68 reciprocate downwardly and upwardly as the upwardly biased switch actuating plunger 34 and cam 68 are downwardly and upwardly reciprocated by the pushbutton plunger 40. The plunger 40 pushes downwardly on the central ring 120 and fingers 70 of cam 68 and plunger 34 from the positions of FIG. 4 to FIG. 5. Then the plunger 40 releases slightly upwardly to the position of FIG. 6, then down and up repeatedly to actuate and unactuate the switch means 44. Then the plunger 40 pushes slightly downwardly and releases upwar-dly until the lamp holder 26 and pushbutton 30 are pulled outwardly of the casing 20, leaving the fingers 70 to be moved into new serration notches 87 as indicated in FIG. 9A, in a manner to be more fully described.

The serrated member 86 may be a cylindrical serrated member with a plurality of cylindrically arranged downward indentations 87 which are substantially aligned with the cylindrically arranged slanting surfaces 110, stop notches 112 and intermediate grooves 102, and in which the plurality of fingers 70 slidingly engage said cylindrically arranged downward serrations 87.

The switch actuating plunger 34 is upwardly biased by the compression spring 122. The ends of spring 122 engage the case bottom 109 and the plunger disc 90. Such spring 122 causes the plunger disc 90* to move upwardly as far as permitted by cooperating members. The plunger 34 has an upper extension 124, FIG. 3, which receives the ring 120' of the cam 68 and around which the ring 120 rotates.

The cam 68 has finger means or fingers 70 each of which has a single slanting bottom edge 126 and a double slanting surface upper ridge 128, FIGS. 2, 2A, 3, 4A, 5A, etc. The lower edges 126 of fingers 70 extend below the lower surface of the cam ring 120 so that such edges 126 can ride on the upper flat surface 92 of the plunger disc without interference from the ridges 94 under certain conditions, such as shown in FIGS. 4A, 6A, 6B and 9A. The double upper ridges 128 can engage the under surfaces of the downward serrations 87 of serrated member 86, as shown in FIG. 4A.

When the cam ring 120 and fingers 70 and plunger 34 are not pushed down by pushbutton plunger 40, as in FIGS. 4 and 4A, the lower edge 126 of each finger 70 rides on the upper flat surface 92 of plunger disc 90, and the upper edge 128 of each finger 70 extends into a downward serration 87 of the serrated member 86.

When the pushbutton 30 and the pushbutton plunger 40 are pushed down to the position of FIGS. 5 and 5A, the plunger 40 pushes the cam ring 120, each finger 70 and lower finger edge 126 downwardly so that lower edge 126 rides down upper slanting surface to rotate the cam 68 and each finger 70 until each lower edge 126 is positively stopped by the corresponding stop notch 112, as in FIG. 5A. This positively stops the downward motion of plunger 34 and of the pushbutton 30, so that the user or operator must release the pushbutton 30 slightly upward, as in FIGS. 6 and 6A to permit the lower edge 126 of each finger 70 to be lifted above the stop notch 112. The upper ridge 128 is also lifted upwardly at this time, with the aid of ridge 94 so that upper ridge 128 engages the next leftward downward serration 87, as indicated in FIG. 6A, so that such finger 70 is rotated leftwardly slightly in readiness to cause the lower edge 126 of such finger to engage the lower slanting surface 114 when the pushbuton 30 is pushed down to cause actuation of the switch means 44.

When the pushbutton 30 is pushed down in FIG. 6, from the position of FIG. 6A, for switch actuation,

the cam 68 and each finger 70 will be pushed down by pushbutton plunger 40 and each lower surface 126 of each finger 70, will slide down along lower surface 114 of FIG. 6A so that such finger will move leftwardly and enter the next leftward groove 102, as shown in FIG. 6B. At the same time the plunger disc 90 will be pushed down by the cam ring so that the plunger 34 will be pushed down to the dotted line switch actuating position 34A of FIG. 6. Thereafter the pushbutton 30 may be upwardly released to the switch unactuation position to move the plunger 34 to the full line position of FIG. 6 as often as desired.

Each finger 70 will likewise move to the dotted upper position and full line lower position shown in FIG. 6B, as often as desired.

This will continue until it is desired to remove the pushbutton 30 and lamp holder 28 from the casing 20 for lamp replacement or the like and for reinsertion into casing 20.

The action of the cam 68 and of each of its fingers 70 during such removal and reinsertion of the pushbutton 30 and lamp holder 28 is shown in FIG. 9A, when considered with FIG. 6B and the positions of the cam 68 and fingers 70 during the positions of the pushbutton plunger 40 as it is moved in the casing 20 during the withdrawing operations of FIGS. 8 and 9 and during the complete withdrawal to the position of FIG. 1 and then to the reinsertion, as in FIG. 4.

While the plunger 40 is moved slightly up in FIG. 8 to move each finger 70 above the normal position of FIG. 6B and then slightly down, as in FIG. 9, such positions of FIGS. 8 and 9 are above the normal positions of FIG. 6B, and each finger 70 reciprocates in and above the groove 102 shown in FIG. 6B, as indicated at FIG. 9A. However, when the pushbutton plunger 40 is completely withdrawn from the casing 20 for lamp replacement and the like, to the position of FIG. 1, then the cam 68 and each cam finger 70 and plunger disc 90 is forced upwardly by compression spring 122 to the highest possible dotted position 70A of FIG. 9A which is in the apex of a new serration 87. This will place the lowest point 130 of each finger 70A slightly leftward of the highest point 132 of a new slanting wall 110A.

When the pushbutton construction 26 of FIG. 1 is then reinserted into the casing 20 and the pushbutton plunger 40 again engages the cam 68, as in FIGS. 4, 5, and 6, the above finger 70A will then move into a new groove 102A which will be the next leftward groove 102 compared to the groove 102 which is utilized by such finger 70 in FIGS. 4A, 5A, 6A and 6B.

This change of grooves 102 occurs whenever the pushbutton construction means 26 is removed from the casing for lamp replacement and the like.

OPERATION In using this invention, the user, or operator, may start with the parts as shown in FIG. 1. The operator holds the pushbutton 30 and inserts the lamp holder 28 first and then the pushbutton 30 into the casing end 22 as shown in FIG. 4. He continues to push the pushbutton 30 inwardly until the lamp holder 28 is stopped by the corner stop 32, FIG. 5. At this time the pushbutton 30 and lamp holder 28 are held together by the legs 46, FIGS. 1 and 7. The pushbutton 30 may be further pushed in with the plunges 38 and 40 pushing down on cam 68 so that each cam finger 70, FIG. 4A pushes down on surface 92 of plunger disc 90.

He continues to push down on push-button 30 so that plunger 40 causes cam 68 and each finger 70 to push plunger disc 90 down, as shown at FIGS. 5 and 5A, so that each finger 70 moves down from its position in FIG. 4A to the dotted line position of FIG. 5A and then slides down slanting surface 110 of guide 98 to the full line position of FIG. 5A where the finger 70 is stopped by stop slot 112. This positively stops finger 70, cam 68, plunger 34 and 40 and pushbutton 30 in the position of FIGS. 5 and 5A, with the locking hooks 58, FIG. 5, under the locking brackets 60 of casing 20.

The user or operator then releases the pushbutton 30, so that the springs 67 and lamp contacts 69 push the lamp holder 28 upward slightly to the position of FIG. 6. This locks the lamp holder 28 in the casing 20 with the hooks 58 engaging the casing brackets 60. At the same time each cam finger 70 is raised to the position of FIG. 6A by the compression spring 122 which acts on the disc 90 and raises the lower end or the finger 70 above the stop notch 112. Thereafter the user or operator may alternately push down and release the pushbutton 30 as often as he desires, and the plunger 36 will alternately actuate the switch means 44, as shown in dotted lines in FIG. 6 and unactuate the switch means 44 as shown in full lines in FIG. 6. This controls any desired circuit and any lamps 80 which may be electrically connected to the switch connectors 78. During this time the full line finger 70 of FIG. 6A slides down slanting surface 114 and reaches the full line position of finger 70 in slot 102 of FIG. 6B during the first actuating push in of pushbutton 30. Thereafter the finger 70 may alternate between the full line and dotted line positions of FIG. 6B in the slot 102 as the pushbutton 30 is pushed down and released to actuate and unactuate the switch means 44 as shown in FIG. 6

When the user or operator desires to remove the pushbutton construction means 26 from the casing 20 for relamping or other purposes, he pulls outwardly on pushbutton 30 as indicated by an arrow in FIG. 7 to pull up on legs 46 to the dotted line position 48A of the leg ends so that the pushbutton 30 is pulled up to the position of FIG. 8. This brings the narrow throat 52 in line with the locking arms 54 ready to permit them to be pushed in by the compression springs 56.

Thereafter the user pushes in slightly on push button 30, as in FIG. 9. This moves the locking arms 54 down below the bracket 60, so that the arms 54 are pushed in against the throat 52. During the movements of the push button 30, as in FIGS. 8 and 9, the plunger 40 has been moved to higher positions than in FIG. 6. This permits the compression spring 122 to push the plunger disc to a higher position than in FIGS. 6A and 6B to the position of FIG. 9A, and higher. As the disc 90 is moved up in FIG. 9A the finger 70 is pushed up against downward serration 87 as shown in full line and farther, to the position shown in dotted lines 70A. As the pushbutton con struction means 26 is pulled out of the casing 20 to the position of FIG. 1, the lower end 1130 of the finger 70A, FIG. 9A is moved leftwardly of the highest point 132 of slanting wall A.

When the pushbutton construction means 26 is reinserted in the casing end 22 and into the positions of FIGS. 4-6, the finger 70A of FIG. 9A will eventually slide down slanting wall 110A, etc., and into new leftward slot 102A of FIG. 9A. The foregoing operations may be repeated as often as desired.

It is thus to be seen that a new, useful and unobvious pushbutton construction has been provided with a positive plunger safety stop.

While the form of the invention now preferred has been disclosed, as required by statute, other forms may be used, all coming within the scope of the claimed subject matter which follows.

What is claimed is:

1. In combination:

a casing having a receiving casing aperture means;

switch means connected with said casing;

pushbutton construction means to actuate and unactuate said switch means and being movable inward relatively to said casing aperture means by a pushing in action; locking means and withdrawing means to lock said pushbutton construction means in switch means actuating and unactuating operable locked condition by an initial locking pushing in action of said pushbutton construction means into said aperture means followed by an initial release of said pushbutton construction means, and to withdraw said pushbutton construction means for said operable locked condition by a pulling out action of said pushbutton construction means, said pushbutton construction means being inwardly actuatable and outwardly releasable to operate said switch means respectively to actuated switch means condition and to unactuated switch means condition while said pushbutton construction means is in said locked operable condition;

safety means to prevent said pushbutton construction means from operating said switch means to actuated condition during said initial locking pushing in action and including a switch actuating plunger movably mounted and retained in a plunger support means carried by said casing independently of said pushbutton construction means, said plunger being movable toward and away from said switch means by said pushbutton construction means to actuate and unactuate said switch means, positive stop means, in said plunger support means, to stop said plunger in said switch means unactuating position during said initial locking pushing in action, and stop inoperative rendering means responsive to said initial release of said pushbutton to render said positive stop means inoperative to stop said plunger in unactuating position.

2. A combination according to claim 1 in which said pulling out action include a releasing pushing in action followed by a complete withdrawal of said pushbutton construction means from said casing.

3. A combination according to claim 1, in which stop reactivating means are provided responsive to said pulling out action includes a releasing pushing in action to reactivate said positive stop means to stop said plunger in unactuating position during a subsequent initial looking pushing in action, which follows a complete removal of said pushbutton construction means from said casing.

4. A combination according to claim 3 in which said positive stop means, said stop inoperative rendering means, and said stop reactivating means include:

a stationary serrated member with downward serrations; said switch actuating plunger; a plunger guide means for said switch actuating plunger; said serrated member, said plunger and said plunger guide means being keyed together so that they cannot substantially rotate with respect to each other, and with said plunger being free to move 1pngitudinally with respect to said serrated member and said plunger guide means; 1

cam means free to rotate between and relatively to said serrated member, said plunger, and said plunger guide means;

said plunger having upward ridges and upward flat surfaces;

said plunger guide means having slanting surfaces with stop notches and intermediate grooves;

said cam means being upwardly and downwardly movable with said plunger;

finger means on and movable with said cam means which engage said serrations, said ridges, said upward fiat surfaces, said slanting surfaces, said stop notches, and enter in and move in said intermediate grooves;

said positive stop means, said stop inoperative rendering means and said stop reactivating means cooperating to cause said positive stop means to stop said switch activating plunger in switch unactuating position during an initial pushing in action of said push button construction means and to reactivate said positive stop means during a subsequent initial locking pushing in action of said push button construction means which follows a complete removal of said push button construction means from said casing.

5. A combination according to claim 4 in which said push button construction means includes a pushbutton means and a lamp holder means, and in which said lamp holder means is positively stopped by easing stop means and said push button means is positively stopped by positive stop means connected with said switch actuating plunger during said initial pushing in action.

6. A combination according to claim 5 in which said pushbutton is movable relatively to said lamp holder means, and said pushbutton means has a pushbutton plunger means passing through said lamp holder means and operating said switch actuating plunger.

7. A combination according to claim 6 in which said pushbutton plunger means engages said cam means and causes said finger means to enter in and move in said intermediate grooves.

8. A combination accarding to claim 7 in which said plunger guide means is a cylindrical plunger guide means with a plurality of identical cylindrically arranged said slanting surfaces with said stop notches and said intermediate grooves, and said cam means and finger means have a plurality of fingers sliding on respective said slanting surfaces, engaging respective said stop notches, and entering and moving in respective said intermediate grooves.

9. A combination according to claim 8, in which said serrated members is a cylindrical serrated member with a plurality of cylindrically arranged downward serrations which are substantially aligned with said cylindrically arranged slanting surfaces, stop notches and intermediate grooves, and in which said plurality of fingers slidingly engage said cylindrically arranged downward serrations.

10. A combination according to claim 9 in which said plurality of fingers enter new intermediate grooves after said pushbutton construction means has been completely removed from said casing and is being reinserted into said casing.

11. A combination according to claim 4 in which said switch actuating plunger has an upper plunger disc.

12. A combination according to claim 11 in which said disc has an upper flat surface.

13. A combination according to claim 12 in which said flat surface has a plurality of ridges.

14. A combination according to claim 13 in which said disc has a plurality of teeth.

15. A combination according to claim 4 in which said plunger guide means is a cylindrical plunger guide means.

16. A combination according to claim 15 in which said guide means has a plurality of grooves, and said switch actuating plunger has an upper disc with a plurality of teeth engaging said grooves.

17. A combination according to claim 16 in which said guide means has an upper circular end and has a plurality of slanting upper surfaces which extend below and inward of said end which are engaged by said finger means.

18. A combination according to claim 17 in which said slanting surfaces have a plurality of stop notches which are engaged by said finger means.

19. A combination according to claim 18 in which said slanting surfaces have a plurality of continuing lower slanting surfaces extending into said grooves.

20. A combination according to claim 19 in which said guide means has a plurality of inward columns below said slanting surfaces to provide inwardly extending side Walls to produce said grooves between said columns.

21. A combination according to claim 4 in which said serrated member is a cylindrical serrated member with a plurality of cylindrically arranged downward serrations, and in which said plunger guide means is a cylindrical plunger guide means having a plurality of grooves, a plur-ality of slanting upper surfaces, and a plurality of stop notches in substantial alignment with said cylindrically arranged downward serrations.

References Cited UNITED STATES PATENTS 3,090,949 5/1963 Hallerberg 200-159 X 3,158,956 11/1964 McMains. 3,197,598 7/ 1965 Andersen et al. 3,394,403 7/ 1968 Dennison. 3,437,775 4/ 1969 Piber 29-622 X FOREIGN PATENTS 929,828 1/ 1948 France. 1,163,964 10/ 1958 France. 1,223,508 6/ 1960 France.

ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant Examiner U.S. Cl. X.R. 

